For some locations both global and diffuse solar radiation are measured. However, for many locations, only global radiation is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct...

En este artículo se realiza una introducción a la valoración económica en el sector de la numismática. A tal efecto, se describen las variables explicativas más importantes del valor de mercado de una moneda, calculando un modelo de regresión múltiple. Las variables más representativas...

This paper intended to evaluate the determinative factors in the price variation of the purchases through e-bidding in Brazil. A survey in 195 e-bidding winners was carried through to test the relation between the price variation and representative variables of transaction-cost theory. Through...

Nowadays, volatility of crude oil price is one of the important developments which are followed by experts with care. Recently increasing of crude oil price is very important for Turkey which 40% of energy consumption consists of oil and 90% of this amount is imported. The aim of the study is...